1. Field of the Invention
This invention relates to a stapling apparatus and method and to thermoplastic staples used therewith.
2. Prior Art Statement
It is known in the art to provide apparatus for and method of stapling utilizing metal staples.
It is also known to provide a staple consisting of a metal core and a thermoplastic covering material bonded against such core as disclosed in U.S. Pat. No. 3,076,373. Further, it has also been proposed to provide a nail, hook, staple, or the like, made of so-called vulcanite and as disclosed in U.S. Pat. No. 617,064. It is presumed from the disclosure in this latter patent that vulcanite is a hard rubber.
However, there are applications in industry and commerce where it would be desirable to employ staples made entirely of non-metallic thermoplastic material. For example, in the art of making polymeric endless power transmission belts it is common practice to fasten together (employing suitable fasteners) a plurality of webs of sheet material, such as fabric, and then coat the resulting construction on one or both sides with a polymeric material. The coating action may be by calendering, skim coating, frictioning, knife coating, or the like technique. The coated construction is then used in building a belt-defining sleeve which is subsequently cut after curing and cooling thereof to define a plurality of endless power transmission belts. It is desirable that the fasteners employed to fasten the fabric be made of a material which may be readily cut without damage to the cutting device; and, it has been found that staples made of a thermoplastic material have numerous advantages in this type of application.